The proteome of B cell signalling
B lymphocytes communicate with their environment through a variety of receptors. One of which is the functionally predominant B cell antigen receptor (BCR). BCR signaling is essential not only for B lymphopoiesis but also for activation, clonal expansion and terminal differentiation of mature B cells which are central effectors of humoral immunity. To coordinate these complex biological processes the BCR regulates multiple sets of intracellular signaling proteins. As in many signaling pathways reversible protein phosphorylation is a driving force behind receptor mediated changes in protein interaction networks which lead to a rearrangement of the cytoskeleton and altered gene transcription as a prerequisite for the mentioned essential cellular responses.
For a better molecular understanding of BCR signaling we set out to elucidate:
I) the phosphoproteome of B cells upon receptor stimulation
II) the stimulation dependent protein-protein interaction networks within stimulated B lymphocytes
We use SILAC combined with high end mass spectrometry to gain insights into the phosphorylation- and protein interaction dynamics in B lymphocytes. Furthermore, in cooperation with the Department of Cellular and Molecular Immunology, we investigate the functional biological relevance of identified signaling proteins as well as of identified protein-protein interactions in vivo.